/*
 * Copyright (c) 2023-2025 elsfs Authors. All Rights Reserved.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.elsfs.cloud.common.mybatis.ext.sql.support.insert;

import java.util.Collection;
import java.util.Map;
import java.util.stream.Collectors;
import lombok.RequiredArgsConstructor;
import org.elsfs.cloud.common.mybatis.ext.sql.SqlParameterManager;

/** 标准实现 */
@RequiredArgsConstructor
public class StandardValuesItem implements ValuesItem {

  /** SQL参数管理器 */
  protected final SqlParameterManager sqlParameterManager;

  /** 插入字段集合 */
  private final Collection<String> insertFields;

  /** 值集合 */
  private final Collection<Map<String, Object>> values;

  /**
   * 构建SQL片段
   *
   * @return SQL片段
   */
  @Override
  public String buildSqlFragment() {
    if (this.values.isEmpty()) {
      return "VALUES";
    }

    return String.format(
        "VALUES %s",
        this.values.stream()
            .map(
                value ->
                    String.format(
                        "(%s)",
                        this.insertFields.stream()
                            .map(
                                field -> {
                                  Object v = value.get(field);
                                  if (v == null) {
                                    return "NULL";
                                  }

                                  return SqlParameterManager.buildParameterPlaceholder(
                                      this.sqlParameterManager.registerParameter(v));
                                })
                            .collect(Collectors.joining(", "))))
            .collect(Collectors.joining(", ")));
  }
}
